Improvement in direct-acting comfottnd engine



Pazntfed-Aug-2, 1879.`

DIRECT AGTINGJGOMPOUND ENGINE-@v the following is aspeciiication.

, This'nvention is intended as an improvement upon '.I IvILLI AM` M.,-IIENDEnsoN, or PHILADELPHIA, PENNSYLVANIA] Letters Patent Ivo.loactnfdated August 2, '1370.A

IMPRovEMeNrrN manor- ACTING coMPo'UND ENGINE.

,f The` Schedulereferred to in `these Lettere y*Patent and making partof the same L I, `WILLIAIYI M." Hersonissos', of Philadelphia, St-atetof, Pennsylvania, have invented certain improvements inDirect-AictionyCompound=Steam-Engines, of which thepatent granted to myselfV by theUnited States vPatent O ce, dated ,April 5, 1870,ND.`101,617,`for

ari- Improvement in, Direct-Action Compound Steam- Engmes, theimprovement referring exclusively to the mode of operatingthesteam-valves when it is desired `to Work `the engines singly, andnotin pairs, as set forth in the patent above referred to, theAv samebeing directly applicable to the construction of single direct- Yacth'm,engines, as commonly employed for pumping.v purposes, whichengines'invariably take' full-pressure i steam throughout the entirestroke, a consequence at- `tendant upon the general' means employed tooperate 'thersteam-valve,:whicht is alternately reversed'by a I motioncomm unicated fromcthe `steam-piston or its rod, at orabont thetermination ot each stroke, in a variety ot'tfways, eachftlie subject ofan individual patent.

The result 1ct' `thewhole is identical `in theone fea-1 ture, that nogain from expansion can ever be obtained, a matter overlookedas ot minorimportance, so long as the valve can be reversed, but in reality ofygreat I significance, especially Ysowhen an engine of .consider- 1 ablesize isreqnired, where economy of fuel is a desid- 'eratum. In thisengine the means employed to'eect this end is by the use of combinedhigh and low pressure steam-cylinders, fitted with slide-valves of apeculiar form, connected with small steam-pistons, which valvesareentirely free from contact with the main pistons or rod, and movedexclusively by the duid em" ployed as a motive power, the valvescontrolling the motion of the main pistons, and said pistons control--ling the necessary motion' of the valves at theright time, to cause theu /hol'etov nperateantomatically with any degree of determinedexpansiom4allfof which will,

' be hereafter more fully described, reference lie-inghad I totheaccompanyingdrawing, 'and' to the letters. of.'

reference marked thereon, which shows alongitudinal section of thisimprovement, exhibiting the combinedcylinders, with the generalarrangementpf-,the-fpistons,

ports, and valves, and means for operatm A is a steam-cylinder, closedat e'ac` i B B, and divided into two lequal parts b'y' an abutment, O,formed into a stuug-boir, and packetlwith n'letal-v lic packing-rings,as sho\vn.

Dis a hollowtrunk, turned to suit the -boreof this `E E', ata distanceapart equal tothe length of the.

` stroke of the engine, added to the width Vof the central abutment,and'the clearance allowed'.A 4Each pistoncylinder engines, in orderto'permit each piston, E E', to have the stroke determined-upon. i` n iThe piston-rodFis-attached to the tinnkD,`-as shown, and passes througha stuiing-box in the front ,cylinder-head B'.

G G are polts for admittingv the live steam from the steaxmchest to theannular cylinders' H H', formed by. the above-describedA combinationot'l parts.

- lI Il are transfer portsfor conducting the steam'frorn the annular-orhigh-pressure cylinders to the low pressure cylinders A A', -and `J vJare eduction ports for exhausting the spent steam, v j

KK are two similar slide-valves, connected and moved together by'arod,L, which is furnished with a yoke, as'sllown, fitted with aslidingblOcE'intowhicli a wrist-pin of a crank-arm, M,projectspthegshaft of this crank passes through a stuing-box to theoutside I vIn each "end ofthe valvechest is formed' a small cylinder,bored true vin linewith each other, and tted with steam-pistons N N',packed with metallic packidg"-rings. Theinner ends of these cylindersare open i to the steam within the valve-ches,t, and consequentlybalance-each other, being both exposed to thel same pressure. The outerends `of the cylinders are closed by heads O 0.', 'as shown. Thesepistons are attached tothe valves K K by rods P P", and fconstitnte `thev mechanism by which the slide-valves are opera-ted.l

' Steam`passag`es,'fQ Q', are cut through from these small cylindersin'to the transferports I IY', as indicated. The 'rods P1 are continuedthrough studing-boxe's'in :the `heads O- 0", and their extremitiesttedwith dash. 'j'

pots, t'o break theA -force ofthe movement ofthe valves,

by cushioning, in any of the well-known jrnethods.'y 't Each slide-valvehas'a' steamf-passage o r'port cored through it, to establish, at theproperAtime, a comrnu nication between the .ports G and I, for thepurpose of conducting the live steam from the highfpressure to vthelow-pressure steam-cylinders, .as before dev scribed. fj In'otherrespects the faces 'of these valves'- -are made to coincide with the.ports over which they play v iid'vofthe boreof the cylinder A, ct downto the level of the counter-bore, the apen; 0f the V of each-poutingtoward each other; `these are cushioningpassages for arrestingthe pistonsll E'at the vends (aftheir stroke, and at the saine time areaiso thev steamports f oradmitting the; steam to the valve-pistons,cause areversion ofthe position of the slide-valves',

, the main pistons acting at thatl time asA the slide-valve y for thesmall'pistons.

W is where the steam` enters the chest fromthe boiler, and itsy`distribution is-eftected as follows; i

Referring to the drawinmwe nd the pistonailier?1 R' are small V-shapeflcavities arranged at each' ingjust completed the stroketo the left. Livesteam' has been admitted by the port G, while the spent 'steam from theother side oi' the piston E has beeii` exhausted through the port J intotlieexhaust-chamber S, thence conveyed away by afpipe, T, in the usualmanner,'to the condenser, or dischargedl into the atmosphere, as thecase may be. b

It will lat the saine time be observed that the charge of live steamfrom the previous stroke, after imp'clling thepiston E to the right, hasbeen transferred by the poits G', K', and 1', to the low-pressurecylinderAi',

where it has been assisting the-efforts of the live steampressing uponthel piston-head E, by exerting its expansive force upon the greaterarea presented by the face of the piston lIE.

The eiective area alici-ded here is reduced to that of the trunkonly,-as the steam, in expanding within the 'low-pressurecylindei,reacts with a back pressure upon the annular or higl'i-pressnrecylinder, as will be at once .apparent by au examination of the actionof the valve K. This, however, does no harm; lnothing is lost inconsequence, and we only require to make the low-pressure cylindersomewhat larger `to compensate for it'.

The present position of the poits shows that the -piston E has justpassed over the exhaust-port J, ef

fectually shutting oif all communication between the end of the.cylinderA and the condenser or atmosphere',

' the engine being condensing or iioii-coiidensing, and

that, immediately following upon this, the inner edge of the samepiston-head passes over the ciishioningpassage R, permitting the livesteam to tiow to the' greater area presented by this piston, asindicated by Athe arrow, thus bi'iiigingthe stroke to yan end. This'same steam immediately rushes up thetiansfer-port I,

and through the passage Q,-to the. endof pistou N.

Now, by virtue of the fact that the steam contained within the cylinderA' has -becomereduced hyexpainsive working, in the proportionof therelative capacities o t' the annular cylinder H' to that of thelowpressure cylinder A', the pressure acting'upon the other piston,:N',is inferior to that just admitted to piston N, consequently theslide-valves must be carried to theriglit by this superior force, which,changing the'dircction of the currents of the s team. by a reversion ofposition of the slide-valves, thereturn Vstroke will be made, afterward:tobe Iarrested,landftl iej valves'again reversed precisely in a similarmannerto that just desciibed, which, being repeated-at the. end of eachstroke, will cause alternate reciprocation' of the pistons and valves adinfinitum, so long as the. steam is admittedto the engine. It is obviousthat the exhaustports should be surely closed vby the piston-headsbefore the established cushion-.passages permit the steam to pass to theends of y the cylinders', otherwise there would vbe a waste. of

steam'; as'it is, no loss is entailed, as the little steam 'that ispassed to perform'lthe functions of 'arresting the pistou and reversingthe valve is merely an ad, vance of the' main body, which, immediatelyafter the valve is reversed, pours over, by th'eport in the valve.

K, to continue its further service of expansion.

Byv arranging the V-shaped passages as described, with the apex of eachpointing 4toward each'other, the cushioning is effected in a verygradual manner,

and the pistons will notl be so suddenly checked, as

would be the case if these passagesopened abruptly. i

- With a further view of regulating tbecushioning."

ports to a greater degree of nicety,the 'steam might be conveyed by la'closed passage, iittedl with a valve,

in place of the countersunkVfpassage just described.

I claim as my invent-ion- 1, In a compound engine,.as described; wherethey opposite faces ofeach piston presents an unequal area,

the arrangement of the passagesR R', eduction-ports J J andsteam-passages Q Q', or their equivalent/s., in combination with themain pistons E E' and wilyer pistons N N', iii such manner that' thelive, steam, upoiifthe completion of each stroke, will pass directly.

from 'the annular cylinders to the valve-pistons N, by the passages Rand Q, for the purpose of operating.'4 thevalves, as described.,

2. Tn@ siidevaives, admitting me impeiiing'agnt employed tothe m""iipistons, which, ii1turn,"aud at l the proper time, become'valves forcontrolling the acq" tion of the slide-valve pistons, the one admittingthe impelling agent tothe other alternately, substantially'.

inthe' manner and for the purposes repiesented.-

, l WILLIAM 'M. HENDERSON. Witnesses:

Josnin H. WARRINGToN, Ro'r. F. LYTLE.

